WPP's GroupM Names Xaxis CEO Brian Lesser North American CEO

As traditional media businesses cede share to new digital ad formats, and technology changes the way those digital ads are bought and sold, WPP's GroupM is suiting itself up with new, technology-savvy leadership and resources.

On the heels of acquiring its first digital media buying shop this week, the network is naming Brian Lesser, CEO of GroupM data and digital buying arm Xaxis, to assume the role of North American CEO of GroupM.

Mr. Lesser succeeds Kelly Clark, who recently announced plans to step down to spend more time with his family. Brian Gleason, Xaxis' North American CEO, will succeed Mr. Lesser within the digital group.

As part of the changes, GroupM Chief Digital Officer Rob Norman also will take on a North America chairman post in addition to his current role.

"It reflects the direction we're going in in terms of our data and technology and driving that business forward on the back of the investments we made recently," said Dominic Proctor, president, GroupM Global. "Now we're bringing it in line with our management strategy."

"I think the direction of change is always much more clear than the pace of change," Mr. Proctor added, when asked if he could have predicted this kind of appointment for GroupM a couple years ago. "You won't see a sudden and dramatic change. We're not overnight switching dollars from one format to another. I think this simply reflects the direction we've been traveling and it's speeding up."

What Mr. Lesser "represents is the opportunity to really build and execute the platforms on which the rest of the enterprise is built," Mr. Norman said. "He has the technology and management chops to do that."

What Mr. Norman brings to the table as chairman is a broader array of client, vendor and GroupM agency CEO relationships.

Within the past couple of years, WPP has made investments in measurement companies ComScore and Rentrak as well as ad-tech giant AppNexus. It has also formed partnerships with digital media platforms like BuzzFeed and Networked Insights.

While GroupM has been investing in new technology, measurement and data platforms to fulfill a growing interest in digital buying, the appointment of Mr. Lesser is still a change in course for the network, which typically has tapped leaders that have come up in the traditional media buying world.

The appointment of Mr. Lesser also complements the network's recent acquisition of Essence, a digital buying shop that handles much of the digital buying for Google around the world. Essence will be the first digital media shop within GroupM, and its CEO, Christian Juhl, will sit on the executive committee within GroupM.

Prior to running Xaxis, Mr. Lesser was VP-product management and director of product marketing at 24/7 Real Media, a global media and technology firm acquired by WPP in 2007 for $649 million and merged into Xaxis in 2014. 24/7 was a collection of publisher-side technologies, including ad server technology and ad network spinoff Real Media Group.

Xaxis was founded within WPP in 2011 to buy ad impressions in bulk and then add value by applying client data to help advertisers find the right person at the right time across the web.

When Xaxis absorbed the 24/7 brand, Mr. Lesser was promoted to global CEO of the larger global entity.

Since then, the unit has introduced a performance-based offering called Light Reaction, a shift from Xaxis' core digital buying operation, which sells entirely on a cost-per-thousand-impressions metric. Within Light Reaction, clients pay for consumer outcomes, such as sales, leads or downloads based on pre-set goals the agency thinks it can reach across mostly mobile inventory.

Xaxis this year also bought mobile ad-tech company ActionX in an effort to grow its share of mobile ad dollars.